Which one is a bone of skull? 

Options

A. Atlas
B. Femur
C. Tibia
D. Pterygoid.

Explanation

To determine which one is a bone of the skull from the given options, we can follow these steps:

### Step-by-Step Solution:

1. **Identify the Options**: The options provided are atlas, femur, tibia, and pterygoid.

2. **Understand Each Bone**:
- **Atlas**: This is the first cervical vertebra in the spine that supports the skull. It is not part of the skull.
- **Femur**: This is the thigh bone, which is the longest bone in the human body. It is not part of the skull.
- **Tibia**: This is the shin bone, located in the lower leg. It is also not part of the skull.
- **Pterygoid**: This is a paired bone that forms part of the palate in many vertebrates. In humans, it becomes the pterygoid processes of the sphenoid bone, which is indeed part of the skull.

3. **Conclusion**: After analyzing the options, the only bone that is part of the skull is the **pterygoid**.

### Final Answer:
The correct option is **pterygoid** as it is a bone of the skull.

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